Related Clues:

• Indication of doom
• Words from a blackmailer
• Time bomb, say
• Sand trap, for one
• Ultimatum, for example
• Links challenge
• Thug's message
• Black ice, e.g.
• Bully's remark
• Impending danger
• Blackmail tactic
• Menacing words
• Sand trap, e.g.
• It might be idle
• Endangerment